Vertical motors are commonly used in many pump applications in, e.g., agricultural, petrochemical, water, and wastewater industries. Large vertical motors with high thrust often use spherical thrust bearings to accommodate the high load and/or high speed of the motor. As they rotate, these types of thrust bearings may generate a large amount of heat. This heat may be transferred to lubricating oil in an oil sump in which the thrust bearing may be located. Conventional vertical motors typically cool the oil using a water cooling system having one or more passages immersed in the oil sump. However, vertical motors using such water cooling systems may have several disadvantages. For example, a source of suitable water (i.e., water with either no contaminants or an acceptable level of contaminants) may not be available. Also, water with even an acceptable level of contaminants may still over time cause premature failures in the water system and/or thrust bearing. Furthermore, water from the cooling system may eventually leak into the oil sump, contaminating the oil which may then cause premature failure of the thrust bearing. Accordingly, a need exists to provide improved cooling of spherical thrust bearings used in vertical motors.